Uniform Formation of Quantum Dots

1 Self Size-Limiting Growth of Uniform InAs/GaAs Quantum Dots 

The incorporation of In adatoms is suppressed at the strained island edges. However, since the top area of the 3D islands is relaxed, the height limiting cannot be due to the strain. 

a (4x) streak pattern appears, that is, the RHEED pattern changed from a (1x1) spot pattern to a (4 x 2) streak pattern with a (1 x 1) spot [11], Once limited dots with 110 facets are formed. In adatoms are no longer incorporated into the limited dots. Therefore, the dot height is spontaneously limited by the formation of stable facets. As a result, incoming In adatoms are accumulated on the wetting layer (Fig. 3.6b). Excess In adatoms cause the (4x2) streak pattern, which reveals the In-stabilized surface. 

InAs dots, embedded by GaAs capping layers with OML 

and 9 ML coverages, respectively. The capping growth process was calculated by using 1 ML 

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